Modulation of Parabrachial Taste Neurons by Electrical and Chemical Stimulation of the Lateral Hypothalamus and Amygdala

2005 ◽  
Vol 93 (3) ◽  
pp. 1183-1196 ◽  
Author(s):  
Cheng-Shu Li ◽  
Young K. Cho ◽  
David V. Smith
Keyword(s):  
Citric Acid ◽  
Lateral Hypothalamus ◽  
Ingestive Behavior ◽  
Central Nucleus ◽  
Homocysteic Acid ◽  
Quinine Hydrochloride ◽  
Neural Substrate ◽  
Parabrachial Nuclei ◽  
Gustatory Neurons ◽  
Stimulation Of

The lateral hypothalamus (LH) and the central nucleus of the amygdala (CeA) exert an influence on ingestive behavior and are reciprocally connected to gustatory and viscerosensory areas, including the nucleus of the solitary tract (NST) and the parabrachial nuclei (PbN). We investigated the effects of LH and CeA stimulation on the activity of 101 taste-responsive neurons in the hamster PbN. Eighty three of these neurons were antidromically activated by stimulation of these sites; 57 were antidromically driven by both. Of these 83 neurons, 21 were also orthodromically activated—8 by the CeA and 3 by the LH. Additional neurons were excited ( n = 5) or inhibited ( n = 8) by these forebrain nuclei but not antidromically activated. Taste stimuli were: 0.032 M sucrose, 0.032 M sodium chloride (NaCl), 0.032 M quinine hydrochloride (QHCl), and 0.0032 M citric acid. Among the 34 orthodromically activated neurons, more sucrose-best neurons were excited than inhibited, whereas the opposite occurred for citric-acid- and QHCl-best cells. Neurons inhibited by the forebrain responded significantly more strongly to citric acid and QHCl than cells excited by these sites. The effects of electrical stimulation were mimicked by microinjection of dl-homocysteic acid, indicating that cells at these forebrain sites were responsible for these effects. These data demonstrate that many individual PbN gustatory neurons project to both the LH and CeA and that these areas modulate the gustatory activity of a subset of PbN neurons. This neural substrate is likely involved in the modulation of taste activity by physiological and experiential factors.

Efferent projection from the bed nucleus of the stria terminalis suppresses activity of taste-responsive neurons in the hamster parabrachial nuclei

2006 ◽  
Vol 291 (4) ◽  
pp. R914-R926 ◽  
Author(s):  
Cheng-Shu Li ◽  
Young K. Cho
Keyword(s):  
Feeding Behavior ◽  
Electrophysiological Study ◽  
Ingestive Behavior ◽  
Stria Terminalis ◽  
Bed Nucleus ◽  
Descending Modulation ◽  
Efferent Projection ◽  
Neural Substrate ◽  
Parabrachial Nuclei ◽  
Gustatory Neurons

Although the reciprocal projections between the bed nucleus of the stria terminalis (BNST) and the gustatory parabrachial nuclei (PbN) have been demonstrated neuroanatomically, there is no direct evidence showing that the projections from the PbN to the BNST carry taste information or that descending inputs from the BNST to the PbN modulate the activity of PbN gustatory neurons. A recent electrophysiological study has demonstrated that the BNST exerts modulatory influence on taste neurons in the nucleus of the solitary tract (NST), suggesting that the BNST may also modulate the activity of taste neurons in the PbN. In the present study, we recorded from 117 taste-responsive neurons in the PbN and examined their responsiveness to electrical stimulation of the BNST bilaterally. Thirteen neurons (11.1%) were antidromically invaded from the BNST, mostly from the ipsilateral side (12 cells), indicating that a subset of taste neurons in the PbN project their axons to the BNST. The BNST stimulation induced orthodromic responses on most of the PbN neurons: 115 out of 117 (98.3%), including all BNST projection units. This descending modulation on the PbN gustatory neurons was exclusively inhibitory. We also confirmed that activation of this efferent inhibitory projection from the BNST reduces taste responses of PbN neurons in all units tested. The BNST is part of the neural circuits that involve stress-associated feeding behavior. It is also known that brain stem gustatory nuclei, including the PbN, are associated with feeding behavior. Therefore, this neural substrate may be important in the stress-elicited alteration in ingestive behavior.

Activity in the Hypothalamus, Amygdala, and Cortex Generates Bilateral and Convergent Modulation of Pontine Gustatory Neurons

2004 ◽  
Vol 91 (3) ◽  
pp. 1143-1157 ◽  
Author(s):  
Robert F. Lundy ◽  
Ralph Norgren
Keyword(s):  
Citric Acid ◽  
Hypothalamic Stimulation ◽  
Central Nucleus ◽  
Parabrachial Nucleus ◽  
Stimulus Response ◽  
Sodium Appetite ◽  
Response Profiles ◽  
Chemical Selectivity ◽  
Gustatory Neurons ◽  
Stimulation Of

Evidence suggests that centrifugal modulation of brain stem gustatory cells might play a role in the elaboration of complex taste-guided behaviors like conditioned taste aversion and sodium appetite. We previously showed that activity in one forebrain area, the central nucleus of the amygdala (CeA), increased the chemical selectivity of taste cells in the parabrachial nucleus (PBN). The present study investigates how activity in 2 other similarly interconnected forebrain sites, the lateral hypothalamus (LH) and gustatory cortex (GC), might influence PBN gustatory processing in rats. The potential convergence of descending inputs from these sites, as well as the CeA, was also evaluated. After anesthesia (35 mg/kg Nembutal ip), 70 PBN gustatory neurons were tested before, during, and after electrical stimulation of these forebrain sites, while responding to 0.3 M sucrose, 0.1 M NaCl, 0.01 M citric acid, and 0.003 M QHCl. Although each forebrain site modulated taste-evoked responses, more PBN neurons were influenced by stimulation of the GC (67%) and CeA (73%) than of the LH (48%). Activation of cortex (71%) and amygdala (85%) most often produced inhibition, whereas inhibition and excitation occurred equally often during hypothalamic stimulation. Of the neurons tested for convergence ( n = 60), 88% were influenced by ≥1 of the 3 sites. Twenty were modulated by stimulation at all 3 sites and another 17 by 2 of the 3 sites. The net effect of centrifugal modulation was to sharpen the across-stimulus response profiles of PBN cells, particular with regard to the NaCl- and citric acid-best cells.

Taste Responses of Neurons in the Hamster Solitary Nucleus Are Modulated by the Central Nucleus of the Amygdala

2002 ◽  
Vol 88 (6) ◽  
pp. 2979-2992 ◽  
Author(s):  
Cheng-Shu Li ◽  
Young K. Cho ◽  
David V. Smith
Keyword(s):  
Electrical Stimulation ◽  
Signal To Noise Ratio ◽  
Central Nucleus ◽  
Homocysteic Acid ◽  
Excitatory Response ◽  
Afferent Information ◽  
Parabrachial Nuclei ◽  
Evoked Activity ◽  
Stimulation Of

Previous studies have shown a modulatory influence of forebrain gustatory areas, such as the gustatory cortex and lateral hypothalamus, on the activity of taste-responsive cells in the nucleus of the solitary tract (NST). The central nucleus of the amygdala (CeA), which receives gustatory afferent information, also exerts descending control over taste neurons in the parabrachial nuclei (PbN) of the pons. The present studies were designed to investigate the role of descending amgydaloid projections to the NST in the modulation of gustatory activity. Extracellular action potentials were recorded from 109 taste-responsive cells in the NST of urethan-anesthetized hamsters and analyzed for a change in excitability following electrical and chemical stimulation of the CeA. Electrical stimulation of the CeA orthodromically modulated 36 of 109 (33.0%) taste-responsive NST cells. An excitatory response was observed in 33 (30.28%) cells. An initial decrease in excitability to electrical stimulation of the CeA, suggestive of postsynaptic inhibition, was observed in three (2.75%) NST taste cells. NST cells modulated by the CeA were significantly less responsive to taste stimuli than cells that were not. Many of these cells were under the modulatory influence of the contralateral CeA (28/36 = 77.8%) as well as the ipsilateral (22/36 = 61.1%); 14 (38.9%) were excited bilaterally. Latencies for excitation were longer after ipsilateral than after contralateral CeA stimulation. Microinjection of dl-homocysteic acid (DLH) into the CeA mimicked the effect of electrical stimulation on each of the nine cells tested: DLH excited eight and inhibited one of these electrically activated NST cells. Application of subthreshold electrical stimulation to the CeA during taste trials increased the taste responses of every CeA-responsive NST cell ( n = 7) tested with this protocol. These effects would enhance taste discriminability by increasing the signal-to-noise ratio of taste-evoked activity.

Parabrachial units responding to stimulation of buffer nerves and forebrain in the cat

1983 ◽  
Vol 245 (6) ◽  
pp. R811-R819 ◽  
Author(s):  
D. F. Cechetto ◽  
F. R. Calaresu
Keyword(s):  
Nerve Stimulation ◽  
Carotid Sinus ◽  
Respiratory Control ◽  
Firing Frequency ◽  
Central Nucleus ◽  
Paraventricular Nuclei ◽  
Control Signals ◽  
Parabrachial Nuclei ◽  
Excitatory Responses ◽  
Stimulation Of

Spontaneously firing units in the region of parabrachial nuclei (PB) and Kolliker-Fuse nuclei (KF) of 19 chloralose-anesthetized cats were monitored for changes in firing frequency during electrical stimulation of carotid sinus (CSN) and aortic depressor (ADN) nerves, of central nucleus of the amygdala (ACE), and of paraventricular nuclei of the hypothalamus (PVH). In the ipsilateral PB 64 of 189 and in the contralateral PB 9 of 103 units responded to CSN stimulation; 18 of 185 ipsilaterally and 7 of 97 contralaterally responded to ADN stimulation. Responses were primarily excitatory, and units were located primarily in the ventrolateral portion of the PB. Only 9 of 267 units responded to stimulation of both CSN and ADN. Stimulation of the ACE and PVH antidromically activated 9 and 7 units, respectively, in PB and approximately half of these also responded to buffer nerve stimulation. In the ipsilateral PB 56 of 207 and in the contralateral PB 11 of 103 units responded orthodromically to ACE stimulation, and 23 of 177 ipsilaterally and 2 of 103 contralaterally responded orthodromically to PVH stimulation with primarily excitatory responses and were located primarily in the ventrolateral portion of the PB and KF. Of these units approximately half also responded to buffer nerve stimulation. These results suggest an important role for PB-KF in mediating ascending and descending cardiovascular and respiratory control signals.

Development of taste responses in the rat parabrachial nucleus

1987 ◽  
Vol 57 (2) ◽  
pp. 481-495 ◽  
Author(s):  
D. L. Hill
Keyword(s):  
Citric Acid ◽  
Hydrochloric Acid ◽  
Age Groups ◽  
Developmental Differences ◽  
Average Response ◽  
Chorda Tympani Nerve ◽  
Ontogenetic Changes ◽  
Quinine Hydrochloride ◽  
Sodium Saccharin ◽  
Parabrachial Nuclei

Extracellular responses from neurons in the parabrachial nuclei (PBN) were studied in rats 4 days old to adulthood during chemical stimulation of the tongue with monochloride salts, citric and hydrochloric acids, sucrose, sodium saccharin, and quinine hydrochloride. Multiunit taste responses were recorded in rats at 4-7 days of age and single-unit responses were recorded from 121 neurons in four other age groups of 14-20 days, 25-35 days, 50-60 days, and adults. PBN neurons in rats 4-7 days old consistently responded to 0.1 M solutions of NH4Cl and NaCl, to 0.5 M solutions of NH4Cl, NaCl, and KCl, and to 1.0 M sucrose, 0.1 M sodium saccharin, 0.1 M citric acid, and 0.1 N HCl. They often did not respond, however, to 0.1 M KCl and 0.01 M quinine hydrochloride. Single PBN neurons in rats 14 days old and older characteristically responded to all stimuli, which consisted of 0.1 and 0.5 M salts, acids, sucrose, sodium saccharin, and quinine hydrochloride. Thus no developmental differences occurred in the number of stimuli to which neurons responded after rats were 14 days old. With the exception of responses to hydrochloric acid, there were significant increases in response frequencies to all stimuli after 14 days of age. Average response frequencies to NH4Cl and citric acid increased after 20 days of age and those to NaCl, LiCl, KCl, sucrose, sodium saccharin, and quinine hydrochloride increased after 35 days of age. Average response frequencies for hydrochloric acid did not alter after 14 days of age. The proportion of single PBN neurons that responded maximally to specific monochloride salts did not change during development. Most single neurons in all age groups responded equally well to NH4Cl, NaCl, and LiCl. No PBN neuron responded maximally to KCl. Developmental differences in response frequencies of third-order gustatory neurons in the PBN generally reflect developmental response changes in first-order neurons of the chorda tympani nerve and second-order neurons of the solitary nucleus. However, unique developmental changes are evident in the PBN. Thus the ontogenetic changes that occur in PBN responses likely relate to modifications of lower-order peripheral and central nervous system afferents and peripheral receptor sensitivities.

scholarly journals Amygdalofugal Influence on Processing of Taste Information in the Nucleus of the Solitary Tract of the Rat

2010 ◽  
Vol 104 (2) ◽  
pp. 726-741 ◽  
Author(s):  
Yi Kang ◽  
Robert F. Lundy
Keyword(s):  
Electrical Stimulation ◽  
Citric Acid ◽  
Neural Coding ◽  
Central Nucleus ◽  
Perceptual Similarity ◽  
Gustatory System ◽  
Solitary Tract ◽  
Neurophysiological Mechanism ◽  
Central Synapse ◽  
Stimulation Of

Previous studies have shown that corticofugal input to the first central synapse of the ascending gustatory system, the nucleus of the solitary tract (NST), can alter the way taste information is processed. Activity in other forebrain structures, such as the central nucleus of the amygdala (CeA), similarly influence activation of NST taste cells, although the effects of amygdalofugal input on neural coding of taste information is not well understood. The present study examined responses of 110 NST neurons to 15 taste stimuli before, during, and after electrical stimulation of the CeA in rats. The taste stimuli consisted of different concentrations of NaCl (0.03, 0.1, 0.3 M), sucrose (0.1, 0.3, 1.0 M), citric acid (0.005, 0.01 M), quinine HCl (0.003, 0.03 M), and 0.03 M MSG, 0.1 M KCl, as well as 0.1 M NaCl, 0.01 M citric acid, and 0.03 M MSG mixed with 10 μM amiloride. In 66% of NST cells sampled (73/110) response rates to the majority of effective taste stimuli were either inhibited or augmented. Nevertheless, the magnitude of effect across stimuli was often differential, which provides a neurophysiological mechanism to alter neural coding. Subsequent analysis of across-unit patterns showed that amygdalofugal input plays a role in shaping spatial patterns of activation and could potentially influence the perceptual similarity and/or discrimination of gustatory stimuli by altering this feature of neural coding.

scholarly journals Descending projections from the nucleus accumbens shell excite activity of taste-responsive neurons in the nucleus of the solitary tract in the hamster

2015 ◽  
Vol 113 (10) ◽  
pp. 3778-3786 ◽  
Author(s):  
Cheng-Shu Li ◽  
Da-Peng Lu ◽  
Young K. Cho
Keyword(s):  
Nucleus Accumbens ◽  
Electrophysiological Study ◽  
Neuronal Firing ◽  
Solitary Tract ◽  
Nucleus Accumbens Shell ◽  
Descending Input ◽  
Parabrachial Nuclei ◽  
Gustatory Neurons ◽  
Stimulation Of

The nucleus of the solitary tract (NST) and the parabrachial nuclei (PbN) are the first and second relays in the rodent central taste pathway. A series of electrophysiological experiments revealed that spontaneous and taste-evoked activities of brain stem gustatory neurons are altered by descending input from multiple forebrain nuclei in the central taste pathway. The nucleus accumbens shell (NAcSh) is a key neural substrate of reward circuitry, but it has not been verified as a classical gustatory nucleus. A recent in vivo electrophysiological study demonstrated that the NAcSh modulates the spontaneous and gustatory activities of hamster pontine taste neurons. In the present study, we investigated whether activation of the NAcSh modulates gustatory responses of the NST neurons. Extracellular single-unit activity was recorded from medullary neurons in urethane-anesthetized hamsters. After taste response was confirmed by delivery of sucrose, NaCl, citric acid, and quinine hydrochloride to the anterior tongue, the NAcSh was stimulated bilaterally with concentric bipolar stimulating electrodes. Stimulation of the ipsilateral and contralateral NAcSh induced firings from 54 and 37 of 90 medullary taste neurons, respectively. Thirty cells were affected bilaterally. No inhibitory responses or antidromic invasion was observed after NAcSh activation. In the subset of taste cells tested, high-frequency electrical stimulation of the NAcSh during taste delivery enhanced taste-evoked neuronal firing. These results demonstrate that two-thirds of the medullary gustatory neurons are under excitatory descending influence from the NAcSh, which is a strong indication of communication between the gustatory pathway and the mesolimbic reward pathway.

Descending projections from the nucleus accumbens shell suppress activity of taste-responsive neurons in the hamster parabrachial nuclei

2012 ◽  
Vol 108 (5) ◽  
pp. 1288-1298 ◽  
Author(s):  
Cheng-Shu Li ◽  
Sooyoung Chung ◽  
Da-Peng Lu ◽  
Young K. Cho
Keyword(s):  
Nucleus Accumbens ◽  
Neural Substrates ◽  
Neuronal Firing ◽  
Inhibitory Influence ◽  
Nucleus Accumbens Shell ◽  
Quinine Hydrochloride ◽  
Parabrachial Nuclei ◽  
Taste Stimulation ◽  
Descending Projections ◽  
Stimulation Of

The parabrachial nuclei (PbN), the second central relay for the gustatory pathway, transfers taste information to various forebrain gustatory nuclei and to the gustatory cortex. The nucleus accumbens is one of the critical neural substrates of the reward system, and the nucleus accumbens shell region (NAcSh) is associated with feeding behavior. Taste-evoked neuronal responses of PbN neurons are modulated by descending projections from the gustatory nuclei in the forebrain. In the present study, we investigated whether taste-responsive neurons in the PbN project to the NAcSh and whether pontine gustatory neurons are subject to modulatory influence from the NAcSh in urethane-anesthetized hamsters. Extracellular single-unit activity was recorded in the PbN, and taste responses were confirmed by the delivery of 32 mM sucrose, NaCl, quinine hydrochloride, and 3.2 mM citric acid to the anterior tongue. The NAcSh was then stimulated (0.5 ms, ≤100 μA) bilaterally using concentric bipolar stimulating electrodes. A total of 98 taste neurons were recorded from the PbN. Eighteen neurons were antidromically invaded from the NAcSh, mostly the ipsilateral NAcSh ( n = 16). Stimulation of the ipsilateral and contralateral NAcSh suppressed the neuronal activity of 88 and 55 neurons, respectively; 52 cells were affected bilaterally. In a subset of pontine neurons tested, electrical stimulation of the NAcSh during taste stimulation also suppressed taste-evoked neuronal firing. These results demonstrated that taste-responsive neurons in the PbN not only project to the NAcSh but also are under substantial descending inhibitory influence from the bilateral NAcSh.

scholarly journals INTERACTION BETWEEN OREXIN AND OPIOIDS SYSTEMS OF THE STRUCTURES OF PARAAMYGDALAR COMPLEX IN THE REINFORCING EFFECTS OF SPONTANEOUS AND ACTIVATED SELF-STIMULATION OF THE LATERAL HYPOTHALAMUS

2017 ◽  
Vol 19 (1) ◽  
pp. 37-45
Author(s):  
Petr D Shabanov ◽  
Andrei Andreevich Lebedev ◽  
Vitalii Ivanovich Morozov ◽  
Sergei Vladimirivich Azarenko
Keyword(s):  
Nucleus Accumbens ◽  
Lateral Hypothalamus ◽  
Intraperitoneal Administration ◽  
Central Nucleus ◽  
Stria Terminalis ◽  
Bed Nucleus ◽  
Reinforcing Effects ◽  
Skinner Box ◽  
Self Stimulation ◽  
Stimulation Of

Male Wistar rats were implanted bipolar electrodes into the lateral hypothalamus to study self-stimulation reaction in the Skinner box and microcannulas into the right lateral ventricle and structutes of the paraamygdalar complex (bed nucleus of stria terminalis, central nucleus of amygdala or nucleus accumbens) to study central effects of orexin (5 µg in 5 µl i. v. for an injection) on the reinforcing properties of pharmacological drugs. Intraperitoneal administration of trimeperidine (3 mg/kg), a synthetic opioid, was shown to increase self-stimulation of the lateral hypothalamus in the Skinner box (number of pedal pressings for 10 min) by 51.8%, and sulpiride (5 mg/kg, a small dose), an antagonist of D2 dopamine receptors, did not change but in the large dose (20 mg/kg) decreased self-stimulation by 49.3% (a number of pedal pressings, or self-stimulation frequency within 10 min). At the same time, SB-408124, an antagonist of OX1R receptors and its combination with orexin did not change self-stimulation indexes after intrastructural administration into the bed nucleus of stria terminalis, central nucleus of amygdala or nucleus accumbens. On the background of blockade of OX1R receptors by SB-408124 (1 µg for all structures) trimeperidine reduced their activating action on self-stimulation reaction. Sulpiride (5 mg/kg i. p., a dose not affecting self-stimulation reaction) blocked activating action of trimeperidine after blockade OX1R receptors by SB-408124 (1 µg). The data obtained can suggest that OX1R receptors participate in the reinforcing effects of synthetic opioid trimeperidine and the blockade of them by SB-408124 potentiate antagonist effects of sulpiride on self-stimulation (4 tables, bibliography: 23 refs).

Modulation of activity of gustatory neurons in the hamster parabrachial nuclei by electrical stimulation of the ventroposteromedial nucleus of the thalamus

2008 ◽  
Vol 294 (5) ◽  
pp. R1461-R1473 ◽  
Author(s):  
Limin Mao ◽  
Young K. Cho ◽  
Cheng-Shu Li
Keyword(s):  
Electrical Stimulation ◽  
Inhibitory Response ◽  
Projection Neurons ◽  
Efferent Projection ◽  
Electrophysiological Studies ◽  
Parabrachial Nuclei ◽  
Gustatory Information ◽  
Ventroposteromedial Nucleus ◽  
Gustatory Neurons ◽  
Stimulation Of

The parvicellular part of the ventroposteromedial nucleus of the thalamus (VPMpc) is positioned at the key site between the gustatory parabrachial nuclei (PbN) and the gustatory cortex for relaying and processing gustatory information via the thalamocortical pathway. Although neuroanatomical and electrophysiological studies have provided information regarding the gustatory projection from PbN to VPMpc, the exact relationship between PbN and VPMpc, especially the efferent projection involving VPMpc to PbN, is obscure. Here we investigated the reciprocal connection between these two gustatory relays in urethane-anesthetized hamsters. We recorded from 114 taste-responsive neurons in the PbN and examined their responsiveness to electrical stimulation of the VPMpc bilaterally. Stimulation of either or both of the ipsilateral or contralateral VPMpc antidromically activated 109 gustatory PbN neurons. Seventy-two PbN neurons were antidromically activated after stimulation of both sides of the VPMpc, indicating that taste neurons in the PbN project heavily to the bilateral VPMpc. Stimulation of VPMpc also orthodromically activated 110 of PbN neurons, including 106 VPMpc projection neurons. Seventy-eight neurons were orthodromically activated bilaterally. Among orthodromic activations of the PbN cells, the inhibitory response was the dominant response; 106 cells were inhibited, including 10 neurons that were also excited contralaterally, indicating that taste neurons in the PbN are subject to strong inhibitory control from VPMpc. Moreover, stimulation of VPMpc altered taste responses of the neurons in the PbN, indicating that VPMpc modulates taste responses of PbN neurons. These results may provide functional insight of neural circuitry for taste processing and modulation involving these two nuclei.

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